Design of Machi...

A ball bearing is anticipated to have a life of 400 M. Rev (Mega Revolutions) under an equivalent load of 10 kN, with reliability of 90%.  Now,

A natural feed journal bearing of diameter 50 mm and length 50 mm operating at 20 revolution/second carries a load of 2.0 kN. The lubricant used has a viscosity of 20 mPa s. The radial clearance is 50 μm. The Sommerfield number for the bearing is

In the multiple disc clutch, if there are 6 discs on the driving shaft and 5 discs on the driven shaft, then the number of pairs of contact surfaces will be equal to

A belt having dimensions 25cm × 1.25cm has the ratio of tension 2 and maximum permissible tension is 150 N/cm². The weight of belt material is 1400 N/m. The maximum power that can be transmitted (in kW) is

A rectangular key of 14mm width, 8 mm height and a shaft of 30 mm diameter made up of same material. If the stress concentration is neglected, then the necessary length of the key for the equal shear strength of shaft and key (in mm), will be__

A rotating beam test specimen is subjected to alternating stress between 100 MPa and -130 MPa. Then which of the following statements are true?

A 4 meter long solid circular cylindrical shaft transmits 1600 kW at 500 rpm. The endurance limit of the material is 210 MPa and a factor of safety of 3 is to be used with respect to fatigue failure. Use G = 77.5 GPa. The design diameter ‘D’ of the shaft in metre is

Radial load acting on a ball bearing is 2500 N for the first five revolutions and reduces to 1500 N for the next ten revolutions. The load variations then repeat itself. The expected life of the bearing is 20 million revolutions. The dynamic load capacity of the bearing is _________ N.

A clutch has outer and inner radius of 50 mm and 20 mm respectively. The pressure at inner radius is 2 MPa and coefficient of friction is 0.4. Assuming uniform wear theory, which of the following statements are true?

A shaft of diameter D is subjected to a fluctuating torque of 200 Nm to 600 Nm. By assuming factor of safety (FOS) = 2.5, S_yt = 200 MPa, S_ut = 400 MPa, K_t = 2, q = 0.8, which of the following statements are true?

A spur gear has a module of 3mm, number of teeth 16, a face width of 36 mm and a pressure angle of 20°. It is transmitting a power of 3kW at 20rev/s. taking a velocity factor of 1.5 and a form factor of 0.3, the stress in the gear is about